<?php
/*
 *  $Id: Connection.php 7490 2010-03-29 19:53:27Z jwage $
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * This software consists of voluntary contributions made by many individuals
 * and is licensed under the LGPL. For more information, see
 * <http://www.doctrine-project.org>.
 */

/**
 * Doctrine_Connection
 *
 * A wrapper layer on top of PDO / Doctrine_Adapter
 *
 * Doctrine_Connection is the heart of any Doctrine based application.
 *
 * 1. Event listeners
 *    An easy to use, pluggable eventlistener architecture. Aspects such as
 *    logging, query profiling and caching can be easily implemented through
 *    the use of these listeners
 *
 * 2. Lazy-connecting
 *    Creating an instance of Doctrine_Connection does not connect
 *    to database. Connecting to database is only invoked when actually needed
 *    (for example when query() is being called)
 *
 * 3. Convenience methods
 *    Doctrine_Connection provides many convenience methods such as fetchAll(), fetchOne() etc.
 *
 * 4. Modular structure
 *    Higher level functionality such as schema importing, exporting, sequence handling etc.
 *    is divided into modules. For a full list of connection modules see
 *    Doctrine_Connection::$_modules
 *
 * @package     Doctrine
 * @subpackage  Connection
 * @license     http://www.opensource.org/licenses/lgpl-license.php LGPL
 * @link        www.doctrine-project.org
 * @since       1.0
 * @version     $Revision: 7490 $
 * @author      Konsta Vesterinen <kvesteri@cc.hut.fi>
 * @author      Lukas Smith <smith@pooteeweet.org> (MDB2 library)
 */
abstract class Doctrine_Connection extends Doctrine_Configurable implements Countable, IteratorAggregate, Serializable
{
	/**
	 * @var $dbh                                the database handler
	 */
	protected $dbh;

	/**
	 * @var array $tables                       an array containing all the initialized Doctrine_Table objects
	 *                                          keys representing Doctrine_Table component names and values as Doctrine_Table objects
	 */
	protected $tables           = array();

	/**
	 * $_name
	 *
	 * Name of the connection
	 *
	 * @var string $_name
	 */
	protected $_name;

	/**
	 * The name of this connection driver.
	 *
	 * @var string $driverName
	 */
	protected $driverName;

	/**
	 * @var boolean $isConnected                whether or not a connection has been established
	 */
	protected $isConnected      = false;

	/**
	 * @var array $supported                    an array containing all features this driver supports,
	 *                                          keys representing feature names and values as
	 *                                          one of the following (true, false, 'emulated')
	 */
	protected $supported        = array();

	/**
	 * @var array $pendingAttributes            An array of pending attributes. When setting attributes
	 *                                          no connection is needed. When connected all the pending
	 *                                          attributes are passed to the underlying adapter (usually PDO) instance.
	 */
	protected $pendingAttributes  = array();

	/**
	 * @var array $modules                      an array containing all modules
	 *              transaction                 Doctrine_Transaction driver, handles savepoint and transaction isolation abstraction
	 *
	 *              expression                  Doctrine_Expression_Driver, handles expression abstraction
	 *
	 *              dataDict                    Doctrine_DataDict driver, handles datatype abstraction
	 *
	 *              export                      Doctrine_Export driver, handles db structure modification abstraction (contains
	 *                                          methods such as alterTable, createConstraint etc.)
	 *              import                      Doctrine_Import driver, handles db schema reading
	 *
	 *              sequence                    Doctrine_Sequence driver, handles sequential id generation and retrieval
	 *
	 *              unitOfWork                  Doctrine_Connection_UnitOfWork handles many orm functionalities such as object
	 *                                          deletion and saving
	 *
	 *              formatter                   Doctrine_Formatter handles data formatting, quoting and escaping
	 *
	 * @see Doctrine_Connection::__get()
	 * @see Doctrine_DataDict
	 * @see Doctrine_Expression_Driver
	 * @see Doctrine_Export
	 * @see Doctrine_Transaction
	 * @see Doctrine_Sequence
	 * @see Doctrine_Connection_UnitOfWork
	 * @see Doctrine_Formatter
	 */
	private $modules = array('transaction' => false,
                             'expression'  => false,
                             'dataDict'    => false,
                             'export'      => false,
                             'import'      => false,
                             'sequence'    => false,
                             'unitOfWork'  => false,
                             'formatter'   => false,
                             'util'        => false,
	);

	/**
	 * @var array $properties               an array of connection properties
	 */
	protected $properties = array('sql_comments'        => array(array('start' => '--', 'end' => "\n", 'escape' => false),
	array('start' => '/*', 'end' => '*/', 'escape' => false)),
                                  'identifier_quoting'  => array('start' => '"', 'end' => '"','escape' => '"'),
                                  'string_quoting'      => array('start' => "'",
                                                                 'end' => "'",
                                                                 'escape' => false,
                                                                 'escape_pattern' => false),
                                  'wildcards'           => array('%', '_'),
                                  'varchar_max_length'  => 255,
                                  'sql_file_delimiter'  => ";\n",
                                  'max_identifier_length' => 64,
	);

	/**
	 * @var array $serverInfo
	 */
	protected $serverInfo = array();

	protected $options    = array();

	/**
	 * @var array $supportedDrivers         an array containing all supported drivers
	 */
	private static $supportedDrivers    = array(
                                        'Mysql',
                                        'Pgsql',
                                        'Oracle',
                                        'Mssql',
                                        'Sqlite',
	);
	protected $_count = 0;

	/**
	 * @var array $_userFkNames                 array of foreign key names that have been used
	 */
	protected $_usedNames = array(
            'foreign_keys' => array(),
            'indexes' => array()
	);

	/**
	 * the constructor
	 *
	 * @param Doctrine_Manager $manager                 the manager object
	 * @param PDO|Doctrine_Adapter_Interface $adapter   database driver
	 */
	public function __construct(Doctrine_Manager $manager, $adapter, $user = null, $pass = null)
	{
		if (is_object($adapter)) {
			if ( ! ($adapter instanceof PDO) && ! in_array('Doctrine_Adapter_Interface', class_implements($adapter))) {
				throw new Doctrine_Connection_Exception('First argument should be an instance of PDO or implement Doctrine_Adapter_Interface');
			}
			$this->dbh = $adapter;

			$this->isConnected = true;

		} else if (is_array($adapter)) {
			$this->pendingAttributes[Doctrine_Core::ATTR_DRIVER_NAME] = $adapter['scheme'];

			$this->options['dsn']      = $adapter['dsn'];
			$this->options['username'] = $adapter['user'];
			$this->options['password'] = $adapter['pass'];

			$this->options['other'] = array();
			if (isset($adapter['other'])) {
				$this->options['other'] = array(Doctrine_Core::ATTR_PERSISTENT => $adapter['persistent']);
			}

		}

		$this->setParent($manager);

		$this->setAttribute(Doctrine_Core::ATTR_CASE, Doctrine_Core::CASE_NATURAL);
		$this->setAttribute(Doctrine_Core::ATTR_ERRMODE, Doctrine_Core::ERRMODE_EXCEPTION);

		$this->getAttribute(Doctrine_Core::ATTR_LISTENER)->onOpen($this);
	}

	/**
	 * Check wherther the connection to the database has been made yet
	 *
	 * @return boolean
	 */
	public function isConnected()
	{
		return $this->isConnected;
	}

	/**
	 * getOptions
	 *
	 * Get array of all options
	 *
	 * @return void
	 */
	public function getOptions()
	{
		return $this->options;
	}

	/**
	 * getOption
	 *
	 * Retrieves option
	 *
	 * @param string $option
	 * @return void
	 */
	public function getOption($option)
	{
		if (isset($this->options[$option])) {
			return $this->options[$option];
		}
	}

	/**
	 * setOption
	 *
	 * Set option value
	 *
	 * @param string $option
	 * @return void
	 */
	public function setOption($option, $value)
	{
		return $this->options[$option] = $value;
	}

	/**
	 * getAttribute
	 * retrieves a database connection attribute
	 *
	 * @param integer $attribute
	 * @return mixed
	 */
	public function getAttribute($attribute)
	{
		if ($attribute >= 100 && $attribute < 1000) {
			if ( ! isset($this->attributes[$attribute])) {
				return parent::getAttribute($attribute);
			}
			return $this->attributes[$attribute];
		}

		if ($this->isConnected) {
			try {
				return $this->dbh->getAttribute($attribute);
			} catch (Exception $e) {
				throw new Doctrine_Connection_Exception('Attribute ' . $attribute . ' not found.');
			}
		} else {
			if ( ! isset($this->pendingAttributes[$attribute])) {
				$this->connect();
				$this->getAttribute($attribute);
			}

			return $this->pendingAttributes[$attribute];
		}
	}

	/**
	 * returns an array of available PDO drivers
	 */
	public static function getAvailableDrivers()
	{
		return PDO::getAvailableDrivers();
	}

	/**
	 * Returns an array of supported drivers by Doctrine
	 *
	 * @return array $supportedDrivers
	 */
	public static function getSupportedDrivers()
	{
		return self::$supportedDrivers;
	}

	/**
	 * setAttribute
	 * sets an attribute
	 *
	 * @todo why check for >= 100? has this any special meaning when creating
	 * attributes?
	 *
	 * @param integer $attribute
	 * @param mixed $value
	 * @return boolean
	 */
	public function setAttribute($attribute, $value)
	{
		if ($attribute >= 100 && $attribute < 1000) {
			parent::setAttribute($attribute, $value);
		} else {
			if ($this->isConnected) {
				$this->dbh->setAttribute($attribute, $value);
			} else {
				$this->pendingAttributes[$attribute] = $value;
			}
		}

		return $this;
	}

	/**
	 * getName
	 * returns the name of this driver
	 *
	 * @return string           the name of this driver
	 */
	public function getName()
	{
		return $this->_name;
	}

	/**
	 * setName
	 *
	 * Sets the name of the connection
	 *
	 * @param string $name
	 * @return void
	 */
	public function setName($name)
	{
		$this->_name = $name;
	}

	/**
	 * getDriverName
	 *
	 * Gets the name of the instance driver
	 *
	 * @return void
	 */
	public function getDriverName()
	{
		return $this->driverName;
	}

	/**
	 * __get
	 * lazy loads given module and returns it
	 *
	 * @see Doctrine_DataDict
	 * @see Doctrine_Expression_Driver
	 * @see Doctrine_Export
	 * @see Doctrine_Transaction
	 * @see Doctrine_Connection::$modules       all availible modules
	 * @param string $name                      the name of the module to get
	 * @throws Doctrine_Connection_Exception    if trying to get an unknown module
	 * @return Doctrine_Connection_Module       connection module
	 */
	public function __get($name)
	{
		if (isset($this->properties[$name])) {
			return $this->properties[$name];
		}

		if ( ! isset($this->modules[$name])) {
			throw new Doctrine_Connection_Exception('Unknown module / property ' . $name);
		}
		if ($this->modules[$name] === false) {
			switch ($name) {
				case 'unitOfWork':
					$this->modules[$name] = new Doctrine_Connection_UnitOfWork($this);
					break;
				case 'formatter':
					$this->modules[$name] = new Doctrine_Formatter($this);
					break;
				default:
					$class = 'Doctrine_' . ucwords($name) . '_' . $this->getDriverName();
					$this->modules[$name] = new $class($this);
			}
		}

		return $this->modules[$name];
	}

	/**
	 * returns the manager that created this connection
	 *
	 * @return Doctrine_Manager
	 */
	public function getManager()
	{
		return $this->getParent();
	}

	/**
	 * returns the database handler of which this connection uses
	 *
	 * @return PDO              the database handler
	 */
	public function getDbh()
	{
		$this->connect();

		return $this->dbh;
	}

	/**
	 * connect
	 * connects into database
	 *
	 * @return boolean
	 */
	public function connect()
	{
		if ($this->isConnected) {
			return false;
		}

		$event = new Doctrine_Event($this, Doctrine_Event::CONN_CONNECT);

		$this->getListener()->preConnect($event);

		$e     = explode(':', $this->options['dsn']);
		$found = false;

		if (extension_loaded('pdo')) {
			if (in_array($e[0], self::getAvailableDrivers())) {
				try {
					$this->dbh = new PDO($this->options['dsn'], $this->options['username'],
					(!$this->options['password'] ? '':$this->options['password']), $this->options['other']);

					$this->dbh->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
				} catch (PDOException $e) {
					throw new Doctrine_Connection_Exception('PDO Connection Error: ' . $e->getMessage());
				}
				$found = true;
			}
		}

		if ( ! $found) {
			$class = 'Doctrine_Adapter_' . ucwords($e[0]);

			if (class_exists($class)) {
				$this->dbh = new $class($this->options['dsn'], $this->options['username'], $this->options['password'], $this->options);
			} else {
				throw new Doctrine_Connection_Exception("Couldn't locate driver named " . $e[0]);
			}
		}

		// attach the pending attributes to adapter
		foreach($this->pendingAttributes as $attr => $value) {
			// some drivers don't support setting this so we just skip it
			if ($attr == Doctrine_Core::ATTR_DRIVER_NAME) {
				continue;
			}
			$this->dbh->setAttribute($attr, $value);
		}

		$this->isConnected = true;

		$this->getListener()->postConnect($event);
		return true;
	}

	public function incrementQueryCount()
	{
		$this->_count++;
	}

	/**
	 * converts given driver name
	 *
	 * @param
	 */
	public function driverName($name)
	{
	}

	/**
	 * supports
	 *
	 * @param string $feature   the name of the feature
	 * @return boolean          whether or not this drivers supports given feature
	 */
	public function supports($feature)
	{
		return (isset($this->supported[$feature])
		&& ($this->supported[$feature] === 'emulated'
		|| $this->supported[$feature]));
	}

	/**
	 * Execute a SQL REPLACE query. A REPLACE query is identical to a INSERT
	 * query, except that if there is already a row in the table with the same
	 * key field values, the REPLACE query just updates its values instead of
	 * inserting a new row.
	 *
	 * The REPLACE type of query does not make part of the SQL standards. Since
	 * practically only MySQL and SQLIte implement it natively, this type of
	 * query isemulated through this method for other DBMS using standard types
	 * of queries inside a transaction to assure the atomicity of the operation.
	 *
	 * @param                   string  name of the table on which the REPLACE query will
	 *                          be executed.
	 *
	 * @param   array           an associative array that describes the fields and the
	 *                          values that will be inserted or updated in the specified table. The
	 *                          indexes of the array are the names of all the fields of the table.
	 *
	 *                          The values of the array are values to be assigned to the specified field.
	 *
	 * @param array $keys       an array containing all key fields (primary key fields
	 *                          or unique index fields) for this table
	 *
	 *                          the uniqueness of a row will be determined according to
	 *                          the provided key fields
	 *
	 *                          this method will fail if no key fields are specified
	 *
	 * @throws Doctrine_Connection_Exception        if this driver doesn't support replace
	 * @throws Doctrine_Connection_Exception        if some of the key values was null
	 * @throws Doctrine_Connection_Exception        if there were no key fields
	 * @throws PDOException                         if something fails at PDO level
	 * @ return integer                              number of rows affected
	 */
	public function replace(Doctrine_Table $table, array $fields, array $keys)
	{
		if (empty($keys)) {
			throw new Doctrine_Connection_Exception('Not specified which fields are keys');
		}
		$identifier = (array) $table->getIdentifier();
		$condition = array();

		foreach ($fields as $fieldName => $value) {
			if (in_array($fieldName, $keys)) {
				if ($value !== null) {
					$condition[] = $table->getColumnName($fieldName) . ' = ?';
					$conditionValues[] = $value;
				}
			}
		}

		$affectedRows = 0;
		if ( ! empty($condition) && ! empty($conditionValues)) {
			$query = 'DELETE FROM ' . $this->quoteIdentifier($table->getTableName())
			. ' WHERE ' . implode(' AND ', $condition);

			$affectedRows = $this->exec($query, $conditionValues);
		}

		$this->insert($table, $fields);

		$affectedRows++;

		return $affectedRows;
	}

	/**
	 * deletes table row(s) matching the specified identifier
	 *
	 * @throws Doctrine_Connection_Exception    if something went wrong at the database level
	 * @param string $table         The table to delete data from
	 * @param array $identifier     An associateve array containing identifier column-value pairs.
	 * @return integer              The number of affected rows
	 */
	public function delete(Doctrine_Table $table, array $identifier)
	{
		$tmp = array();

		foreach (array_keys($identifier) as $id) {
			$tmp[] = $this->quoteIdentifier($table->getColumnName($id)) . ' = ?';
		}

		$query = 'DELETE FROM '
		. $this->quoteIdentifier($table->getTableName())
		. ' WHERE ' . implode(' AND ', $tmp);

		return $this->exec($query, array_values($identifier));
	}

	/**
	 * Updates table row(s) with specified data.
	 *
	 * @throws Doctrine_Connection_Exception    if something went wrong at the database level
	 * @param Doctrine_Table $table     The table to insert data into
	 * @param array $values             An associative array containing column-value pairs.
	 *                                  Values can be strings or Doctrine_Expression instances.
	 * @return integer                  the number of affected rows. Boolean false if empty value array was given,
	 */
	public function update(Doctrine_Table $table, array $fields, array $identifier)
	{
		if (empty($fields)) {
			return false;
		}

		$set = array();
		foreach ($fields as $fieldName => $value) {
			if ($value instanceof Doctrine_Expression) {
				$set[] = $this->quoteIdentifier($table->getColumnName($fieldName)) . ' = ' . $value->getSql();
				unset($fields[$fieldName]);
			} else {
				$set[] = $this->quoteIdentifier($table->getColumnName($fieldName)) . ' = ?';
			}
		}

		$params = array_merge(array_values($fields), array_values($identifier));

		$sql  = 'UPDATE ' . $this->quoteIdentifier($table->getTableName())
		. ' SET ' . implode(', ', $set)
		. ' WHERE ' . implode(' = ? AND ', $this->quoteMultipleIdentifier($table->getIdentifierColumnNames()))
		. ' = ?';

		return $this->exec($sql, $params);
	}

	/**
	 * Inserts a table row with specified data.
	 *
	 * @param Doctrine_Table $table     The table to insert data into.
	 * @param array $values             An associative array containing column-value pairs.
	 *                                  Values can be strings or Doctrine_Expression instances.
	 * @return integer                  the number of affected rows. Boolean false if empty value array was given,
	 */
	public function insert(Doctrine_Table $table, array $fields)
	{
		$tableName = $table->getTableName();

		// column names are specified as array keys
		$cols = array();
		// the query VALUES will contain either expresions (eg 'NOW()') or ?
		$a = array();
		foreach ($fields as $fieldName => $value) {
			$cols[] = $this->quoteIdentifier($table->getColumnName($fieldName));
			if ($value instanceof Doctrine_Expression) {
				$a[] = $value->getSql();
				unset($fields[$fieldName]);
			} else {
				$a[] = '?';
			}
		}

		// build the statement
		$query = 'INSERT INTO ' . $this->quoteIdentifier($tableName)
		. ' (' . implode(', ', $cols) . ')'
		. ' VALUES (' . implode(', ', $a) . ')';

		return $this->exec($query, array_values($fields));
	}

	/**
	 * Quote a string so it can be safely used as a table or column name
	 *
	 * Delimiting style depends on which database driver is being used.
	 *
	 * NOTE: just because you CAN use delimited identifiers doesn't mean
	 * you SHOULD use them.  In general, they end up causing way more
	 * problems than they solve.
	 *
	 * Portability is broken by using the following characters inside
	 * delimited identifiers:
	 *   + backtick (<kbd>`</kbd>) -- due to MySQL
	 *   + double quote (<kbd>"</kbd>) -- due to Oracle
	 *   + brackets (<kbd>[</kbd> or <kbd>]</kbd>) -- due to Access
	 *
	 * Delimited identifiers are known to generally work correctly under
	 * the following drivers:
	 *   + mssql
	 *   + mysql
	 *   + mysqli
	 *   + oci8
	 *   + pgsql
	 *   + sqlite
	 *
	 * InterBase doesn't seem to be able to use delimited identifiers
	 * via PHP 4.  They work fine under PHP 5.
	 *
	 * @param string $str           identifier name to be quoted
	 * @param bool $checkOption     check the 'quote_identifier' option
	 *
	 * @return string               quoted identifier string
	 */
	public function quoteIdentifier($str, $checkOption = true)
	{
		// quick fix for the identifiers that contain a dot
		if (strpos($str, '.')) {
			$e = explode('.', $str);

			return $this->formatter->quoteIdentifier($e[0], $checkOption) . '.'
			. $this->formatter->quoteIdentifier($e[1], $checkOption);
		}
		return $this->formatter->quoteIdentifier($str, $checkOption);
	}

	/**
	 * quoteMultipleIdentifier
	 * Quotes multiple identifier strings
	 *
	 * @param array $arr           identifiers array to be quoted
	 * @param bool $checkOption     check the 'quote_identifier' option
	 *
	 * @return string               quoted identifier string
	 */
	public function quoteMultipleIdentifier($arr, $checkOption = true)
	{
		foreach ($arr as $k => $v) {
			$arr[$k] = $this->quoteIdentifier($v, $checkOption);
		}

		return $arr;
	}

	/**
	 * convertBooleans
	 * some drivers need the boolean values to be converted into integers
	 * when using DQL API
	 *
	 * This method takes care of that conversion
	 *
	 * @param array $item
	 * @return void
	 */
	public function convertBooleans($item)
	{
		return $this->formatter->convertBooleans($item);
	}

	/**
	 * quote
	 * quotes given input parameter
	 *
	 * @param mixed $input      parameter to be quoted
	 * @param string $type
	 * @return string
	 */
	public function quote($input, $type = null)
	{
		return $this->formatter->quote($input, $type);
	}

	/**
	 * Set the date/time format for the current connection
	 *
	 * @param string    time format
	 *
	 * @return void
	 */
	public function setDateFormat($format = null)
	{
	}

	/**
	 * fetchAll
	 *
	 * @param string $statement         sql query to be executed
	 * @param array $params             prepared statement params
	 * @return array
	 */
	public function fetchAll($statement, array $params = array())
	{
		return $this->execute($statement, $params)->fetchAll(Doctrine_Core::FETCH_ASSOC);
	}

	/**
	 * fetchOne
	 *
	 * @param string $statement         sql query to be executed
	 * @param array $params             prepared statement params
	 * @param int $colnum               0-indexed column number to retrieve
	 * @return mixed
	 */
	public function fetchOne($statement, array $params = array(), $colnum = 0)
	{
		return $this->execute($statement, $params)->fetchColumn($colnum);
	}

	/**
	 * fetchRow
	 *
	 * @param string $statement         sql query to be executed
	 * @param array $params             prepared statement params
	 * @return array
	 */
	public function fetchRow($statement, array $params = array())
	{
		return $this->execute($statement, $params)->fetch(Doctrine_Core::FETCH_ASSOC);
	}

	/**
	 * fetchArray
	 *
	 * @param string $statement         sql query to be executed
	 * @param array $params             prepared statement params
	 * @return array
	 */
	public function fetchArray($statement, array $params = array())
	{
		return $this->execute($statement, $params)->fetch(Doctrine_Core::FETCH_NUM);
	}

	/**
	 * fetchColumn
	 *
	 * @param string $statement         sql query to be executed
	 * @param array $params             prepared statement params
	 * @param int $colnum               0-indexed column number to retrieve
	 * @return array
	 */
	public function fetchColumn($statement, array $params = array(), $colnum = 0)
	{
		return $this->execute($statement, $params)->fetchAll(Doctrine_Core::FETCH_COLUMN, $colnum);
	}

	/**
	 * fetchAssoc
	 *
	 * @param string $statement         sql query to be executed
	 * @param array $params             prepared statement params
	 * @return array
	 */
	public function fetchAssoc($statement, array $params = array())
	{
		return $this->execute($statement, $params)->fetchAll(Doctrine_Core::FETCH_ASSOC);
	}

	/**
	 * fetchBoth
	 *
	 * @param string $statement         sql query to be executed
	 * @param array $params             prepared statement params
	 * @return array
	 */
	public function fetchBoth($statement, array $params = array())
	{
		return $this->execute($statement, $params)->fetchAll(Doctrine_Core::FETCH_BOTH);
	}

	/**
	 * query
	 * queries the database using Doctrine Query Language
	 * returns a collection of Doctrine_Record objects
	 *
	 * <code>
	 * $users = $conn->query('SELECT u.* FROM User u');
	 *
	 * $users = $conn->query('SELECT u.* FROM User u WHERE u.name LIKE ?', array('someone'));
	 * </code>
	 *
	 * @param string $query             DQL query
	 * @param array $params             query parameters
	 * @param int $hydrationMode        Doctrine_Core::HYDRATE_ARRAY or Doctrine_Core::HYDRATE_RECORD
	 * @see Doctrine_Query
	 * @return Doctrine_Collection      Collection of Doctrine_Record objects
	 */
	public function query($query, array $params = array(), $hydrationMode = null)
	{
		$parser = Doctrine_Query::create($this);
		$res = $parser->query($query, $params, $hydrationMode);
		$parser->free();

		return $res;
	}

	/**
	 * prepare
	 *
	 * @param string $statement
	 */
	public function prepare($statement)
	{
		$this->connect();

		try {
			$event = new Doctrine_Event($this, Doctrine_Event::CONN_PREPARE, $statement);

			$this->getAttribute(Doctrine_Core::ATTR_LISTENER)->prePrepare($event);

			$stmt = false;

			if ( ! $event->skipOperation) {
				$stmt = $this->dbh->prepare($statement);
			}

			$this->getAttribute(Doctrine_Core::ATTR_LISTENER)->postPrepare($event);

			return new Doctrine_Connection_Statement($this, $stmt);
		} catch(Doctrine_Adapter_Exception $e) {
		} catch(PDOException $e) { }

		$this->rethrowException($e, $this, $statement);
	}

	/**
	 * query
	 * queries the database using Doctrine Query Language and returns
	 * the first record found
	 *
	 * <code>
	 * $user = $conn->queryOne('SELECT u.* FROM User u WHERE u.id = ?', array(1));
	 *
	 * $user = $conn->queryOne('SELECT u.* FROM User u WHERE u.name LIKE ? AND u.password = ?',
	 *         array('someone', 'password')
	 *         );
	 * </code>
	 *
	 * @param string $query             DQL query
	 * @param array $params             query parameters
	 * @see Doctrine_Query
	 * @return Doctrine_Record|false    Doctrine_Record object on success,
	 *                                  boolean false on failure
	 */
	public function queryOne($query, array $params = array())
	{
		$parser = Doctrine_Query::create();

		$coll = $parser->query($query, $params);
		if ( ! $coll->contains(0)) {
			return false;
		}
		return $coll[0];
	}

	/**
	 * queries the database with limit and offset
	 * added to the query and returns a Doctrine_Connection_Statement object
	 *
	 * @param string $query
	 * @param integer $limit
	 * @param integer $offset
	 * @return Doctrine_Connection_Statement
	 */
	public function select($query, $limit = 0, $offset = 0)
	{
		if ($limit > 0 || $offset > 0) {
			$query = $this->modifyLimitQuery($query, $limit, $offset);
		}
		return $this->execute($query);
	}

	/**
	 * standaloneQuery
	 *
	 * @param string $query     sql query
	 * @param array $params     query parameters
	 *
	 * @return PDOStatement|Doctrine_Adapter_Statement
	 */
	public function standaloneQuery($query, $params = array())
	{
		return $this->execute($query, $params);
	}

	/**
	 * execute
	 * @param string $query     sql query
	 * @param array $params     query parameters
	 *
	 * @return PDOStatement|Doctrine_Adapter_Statement
	 */
	public function execute($query, array $params = array())
	{
		$this->connect();

		try {
			if ( ! empty($params)) {
				$stmt = $this->prepare($query);
				$stmt->execute($params);

				return $stmt;
			} else {
				$event = new Doctrine_Event($this, Doctrine_Event::CONN_QUERY, $query, $params);

				$this->getAttribute(Doctrine_Core::ATTR_LISTENER)->preQuery($event);

				if ( ! $event->skipOperation) {
					$stmt = $this->dbh->query($query);
					$this->_count++;
				}
				$this->getAttribute(Doctrine_Core::ATTR_LISTENER)->postQuery($event);

				return $stmt;
			}
		} catch (Doctrine_Adapter_Exception $e) {
		} catch (PDOException $e) { }

		$this->rethrowException($e, $this, $query);
	}

	/**
	 * exec
	 * @param string $query     sql query
	 * @param array $params     query parameters
	 *
	 * @return integer
	 */
	public function exec($query, array $params = array())
	{
		$this->connect();

		try {
			if ( ! empty($params)) {
				$stmt = $this->prepare($query);
				$stmt->execute($params);

				return $stmt->rowCount();
			} else {
				$event = new Doctrine_Event($this, Doctrine_Event::CONN_EXEC, $query, $params);

				$this->getAttribute(Doctrine_Core::ATTR_LISTENER)->preExec($event);
				if ( ! $event->skipOperation) {
					$count = $this->dbh->exec($query);

					$this->_count++;
				}
				$this->getAttribute(Doctrine_Core::ATTR_LISTENER)->postExec($event);

				return $count;
			}
		} catch (Doctrine_Adapter_Exception $e) {
		} catch (PDOException $e) { }

		$this->rethrowException($e, $this, $query);
	}

	/**
	 * rethrowException
	 *
	 * @throws Doctrine_Connection_Exception
	 */
	public function rethrowException(Exception $e, $invoker, $query = null)
	{
		$event = new Doctrine_Event($this, Doctrine_Event::CONN_ERROR);

		$this->getListener()->preError($event);

		$name = 'Doctrine_Connection_' . $this->driverName . '_Exception';

		$message = $e->getMessage();
		if ($query) {
			$message .= sprintf('. Failing Query: "%s"', $query);
		}

		$exc  = new $name($message, (int) $e->getCode());
		if ( ! isset($e->errorInfo) || ! is_array($e->errorInfo)) {
			$e->errorInfo = array(null, null, null, null);
		}
		$exc->processErrorInfo($e->errorInfo);

		if ($this->getAttribute(Doctrine_Core::ATTR_THROW_EXCEPTIONS)) {
			throw $exc;
		}

		$this->getListener()->postError($event);
	}

	/**
	 * hasTable
	 * whether or not this connection has table $name initialized
	 *
	 * @param mixed $name
	 * @return boolean
	 */
	public function hasTable($name)
	{
		return isset($this->tables[$name]);
	}

	/**
	 * returns a table object for given component name
	 *
	 * @param string $name              component name
	 * @return Doctrine_Table
	 */
	public function getTable($name)
	{
		if (isset($this->tables[$name])) {
			return $this->tables[$name];
		}

		$class = sprintf($this->getAttribute(Doctrine_Core::ATTR_TABLE_CLASS_FORMAT), $name);

		if (class_exists($class, $this->getAttribute(Doctrine_Core::ATTR_AUTOLOAD_TABLE_CLASSES)) &&
		in_array('Doctrine_Table', class_parents($class))) {
			$table = new $class($name, $this, true);
		} else {
			$tableClass = $this->getAttribute(Doctrine_Core::ATTR_TABLE_CLASS);
			$table = new $tableClass($name, $this, true);
		}

		return $table;
	}

	/**
	 * returns an array of all initialized tables
	 *
	 * @return array
	 */
	public function getTables()
	{
		return $this->tables;
	}

	/**
	 * returns an iterator that iterators through all
	 * initialized table objects
	 *
	 * <code>
	 * foreach ($conn as $index => $table) {
	 *      print $table;  // get a string representation of each table object
	 * }
	 * </code>
	 *
	 * @return ArrayIterator        SPL ArrayIterator object
	 */
	public function getIterator()
	{
		return new ArrayIterator($this->tables);
	}

	/**
	 * returns the count of initialized table objects
	 *
	 * @return integer
	 */
	public function count()
	{
		return $this->_count;
	}

	/**
	 * addTable
	 * adds a Doctrine_Table object into connection registry
	 *
	 * @param $table                a Doctrine_Table object to be added into registry
	 * @return boolean
	 */
	public function addTable(Doctrine_Table $table)
	{
		$name = $table->getComponentName();

		if (isset($this->tables[$name])) {
			return false;
		}
		$this->tables[$name] = $table;
		return true;
	}

	/**
	 * create
	 * creates a record
	 *
	 * create                       creates a record
	 * @param string $name          component name
	 * @return Doctrine_Record      Doctrine_Record object
	 */
	public function create($name)
	{
		return $this->getTable($name)->create();
	}

	/**
	 * Creates a new Doctrine_Query object that operates on this connection.
	 *
	 * @return Doctrine_Query
	 */
	public function createQuery()
	{
		return Doctrine_Query::create();
	}

	/**
	 * flush
	 * saves all the records from all tables
	 * this operation is isolated using a transaction
	 *
	 * @throws PDOException         if something went wrong at database level
	 * @return void
	 */
	public function flush()
	{
		try {
			$this->beginInternalTransaction();
			$this->unitOfWork->saveAll();
			$this->commit();
		} catch (Exception $e) {
			$this->rollback();
			throw $e;
		}
	}

	/**
	 * clear
	 * clears all repositories
	 *
	 * @return void
	 */
	public function clear()
	{
		foreach ($this->tables as $k => $table) {
			$table->getRepository()->evictAll();
			$table->clear();
		}
	}

	/**
	 * evictTables
	 * evicts all tables
	 *
	 * @return void
	 */
	public function evictTables()
	{
		$this->tables = array();
		$this->exported = array();
	}

	/**
	 * close
	 * closes the connection
	 *
	 * @return void
	 */
	public function close()
	{
		$event = new Doctrine_Event($this, Doctrine_Event::CONN_CLOSE);

		$this->getAttribute(Doctrine_Core::ATTR_LISTENER)->preClose($event);

		$this->clear();

		unset($this->dbh);
		$this->isConnected = false;

		$this->getAttribute(Doctrine_Core::ATTR_LISTENER)->postClose($event);
	}

	/**
	 * get the current transaction nesting level
	 *
	 * @return integer
	 */
	public function getTransactionLevel()
	{
		return $this->transaction->getTransactionLevel();
	}

	/**
	 * errorCode
	 * Fetch the SQLSTATE associated with the last operation on the database handle
	 *
	 * @return integer
	 */
	public function errorCode()
	{
		$this->connect();

		return $this->dbh->errorCode();
	}

	/**
	 * errorInfo
	 * Fetch extended error information associated with the last operation on the database handle
	 *
	 * @return array
	 */
	public function errorInfo()
	{
		$this->connect();

		return $this->dbh->errorInfo();
	}

	/**
	 * getResultCacheDriver
	 *
	 * @return Doctrine_Cache_Interface
	 */
	public function getResultCacheDriver()
	{
		if ( ! $this->getAttribute(Doctrine_Core::ATTR_RESULT_CACHE)) {
			throw new Doctrine_Exception('Result Cache driver not initialized.');
		}

		return $this->getAttribute(Doctrine_Core::ATTR_RESULT_CACHE);
	}

	/**
	 * getQueryCacheDriver
	 *
	 * @return Doctrine_Cache_Interface
	 */
	public function getQueryCacheDriver()
	{
		if ( ! $this->getAttribute(Doctrine_Core::ATTR_QUERY_CACHE)) {
			throw new Doctrine_Exception('Query Cache driver not initialized.');
		}

		return $this->getAttribute(Doctrine_Core::ATTR_QUERY_CACHE);
	}

	/**
	 * lastInsertId
	 *
	 * Returns the ID of the last inserted row, or the last value from a sequence object,
	 * depending on the underlying driver.
	 *
	 * Note: This method may not return a meaningful or consistent result across different drivers,
	 * because the underlying database may not even support the notion of auto-increment fields or sequences.
	 *
	 * @param string $table     name of the table into which a new row was inserted
	 * @param string $field     name of the field into which a new row was inserted
	 */
	public function lastInsertId($table = null, $field = null)
	{
		return $this->sequence->lastInsertId($table, $field);
	}

	/**
	 * beginTransaction
	 * Start a transaction or set a savepoint.
	 *
	 * if trying to set a savepoint and there is no active transaction
	 * a new transaction is being started
	 *
	 * Listeners: onPreTransactionBegin, onTransactionBegin
	 *
	 * @param string $savepoint                 name of a savepoint to set
	 * @throws Doctrine_Transaction_Exception   if the transaction fails at database level
	 * @return integer                          current transaction nesting level
	 */
	public function beginTransaction($savepoint = null)
	{
		return $this->transaction->beginTransaction($savepoint);
	}

	public function beginInternalTransaction($savepoint = null)
	{
		return $this->transaction->beginInternalTransaction($savepoint);
	}

	/**
	 * commit
	 * Commit the database changes done during a transaction that is in
	 * progress or release a savepoint. This function may only be called when
	 * auto-committing is disabled, otherwise it will fail.
	 *
	 * Listeners: onPreTransactionCommit, onTransactionCommit
	 *
	 * @param string $savepoint                 name of a savepoint to release
	 * @throws Doctrine_Transaction_Exception   if the transaction fails at PDO level
	 * @throws Doctrine_Validator_Exception     if the transaction fails due to record validations
	 * @return boolean                          false if commit couldn't be performed, true otherwise
	 */
	public function commit($savepoint = null)
	{
		return $this->transaction->commit($savepoint);
	}

	/**
	 * rollback
	 * Cancel any database changes done during a transaction or since a specific
	 * savepoint that is in progress. This function may only be called when
	 * auto-committing is disabled, otherwise it will fail. Therefore, a new
	 * transaction is implicitly started after canceling the pending changes.
	 *
	 * this method can be listened with onPreTransactionRollback and onTransactionRollback
	 * eventlistener methods
	 *
	 * @param string $savepoint                 name of a savepoint to rollback to
	 * @throws Doctrine_Transaction_Exception   if the rollback operation fails at database level
	 * @return boolean                          false if rollback couldn't be performed, true otherwise
	 */
	public function rollback($savepoint = null)
	{
		return $this->transaction->rollback($savepoint);
	}

	/**
	 * createDatabase
	 *
	 * Issue create database command for this instance of Doctrine_Connection
	 *
	 * @return string       Doctrine_Exception catched in case of failure
	 */
	public function createDatabase()
	{
		if ( ! $dsn = $this->getOption('dsn')) {
			throw new Doctrine_Connection_Exception('You must create your Doctrine_Connection by using a valid Doctrine style dsn in order to use the create/drop database functionality');
		}

		// Parse pdo dsn so we are aware of the connection information parts
		$info = $this->getManager()->parsePdoDsn($dsn);

		// Get the temporary connection to issue the create database command
		$tmpConnection = $this->getTmpConnection($info);

		// Catch any exceptions and delay the throwing of it so we can close
		// the tmp connection
		try {
			$tmpConnection->export->createDatabase($info['dbname']);
		} catch (Exception $e) {}

		// Close the temporary connection used to issue the drop database command
		$this->getManager()->closeConnection($tmpConnection);

		if (isset($e)) {
			throw $e;
		}
	}

	/**
	 * dropDatabase
	 *
	 * Issue drop database command for this instance of Doctrine_Connection
	 *
	 * @return string       success string. Doctrine_Exception if operation failed
	 */
	public function dropDatabase()
	{
		if ( ! $dsn = $this->getOption('dsn')) {
			throw new Doctrine_Connection_Exception('You must create your Doctrine_Connection by using a valid Doctrine style dsn in order to use the create/drop database functionality');
		}

		// Parse pdo dsn so we are aware of the connection information parts
		$info = $this->getManager()->parsePdoDsn($dsn);

		// Get the temporary connection to issue the drop database command
		$tmpConnection = $this->getTmpConnection($info);

		// Catch any exceptions and delay the throwing of it so we can close
		// the tmp connection
		try {
			$tmpConnection->export->dropDatabase($info['dbname']);
		} catch (Exception $e) {}

		// Close the temporary connection used to issue the drop database command
		$this->getManager()->closeConnection($tmpConnection);


		if (isset($e)) {
			throw $e;
		}
	}

	/**
	 * getTmpConnection
	 *
	 * Create a temporary connection to the database with the user credentials.
	 * This is so the user can make a connection to a db server. Some dbms allow
	 * connections with no database, but some do not. In that case we have a table
	 * which is always guaranteed to exist. Mysql: 'mysql', PostgreSQL: 'postgres', etc.
	 * This value is set in the Doctrine_Export_{DRIVER} classes if required
	 *
	 * @param string $info
	 * @return void
	 */
	public function getTmpConnection($info)
	{
		$pdoDsn = $info['scheme'] . ':';

		if ($info['unix_socket']) {
			$pdoDsn .= 'unix_socket=' . $info['unix_socket'] . ';';
		}

		$pdoDsn .= 'host=' . $info['host'];

		if ($info['port']) {
			$pdoDsn .= ';port=' . $info['port'];
		}

		if (isset($this->export->tmpConnectionDatabase) && $this->export->tmpConnectionDatabase) {
			$pdoDsn .= ';dbname=' . $this->export->tmpConnectionDatabase;
		}

		$username = $this->getOption('username');
		$password = $this->getOption('password');

		$conn = $this->getManager()->openConnection(array($pdoDsn, $username, $password), 'doctrine_tmp_connection', false);
		$conn->setOption('username', $username);
		$conn->setOption('password', $password);

		return $conn;
	}

	/**
	 * modifyLimitQuery
	 *
	 * Some dbms require specific functionality for this. Check the other connection adapters for examples
	 *
	 * @return string
	 */
	public function modifyLimitQuery($query, $limit = false, $offset = false, $isManip = false)
	{
		return $query;
	}

	/**
	 * Creates dbms specific LIMIT/OFFSET SQL for the subqueries that are used in the
	 * context of the limit-subquery algorithm.
	 *
	 * @return string
	 */
	public function modifyLimitSubquery(Doctrine_Table $rootTable, $query, $limit = false,
	$offset = false, $isManip = false)
	{
		return $this->modifyLimitQuery($query, $limit, $offset, $isManip);
	}

	/**
	 * returns a string representation of this object
	 * @return string
	 */
	public function __toString()
	{
		return Doctrine_Lib::getConnectionAsString($this);
	}

	/**
	 * Serialize. Remove database connection(pdo) since it cannot be serialized
	 *
	 * @return string $serialized
	 */
	public function serialize()
	{
		$vars = get_object_vars($this);
		$vars['dbh'] = null;
		$vars['isConnected'] = false;
		return serialize($vars);
	}

	/**
	 * Unserialize. Recreate connection from serialized content
	 *
	 * @param string $serialized
	 * @return void
	 */
	public function unserialize($serialized)
	{
		$array = unserialize($serialized);

		foreach ($array as $name => $values) {
			$this->$name = $values;
		}
	}

	/**
	 * Get/generate a unique foreign key name for a relationship
	 *
	 * @param  Doctrine_Relation $relation  Relation object to generate the foreign key name for
	 * @return string $fkName
	 */
	public function generateUniqueRelationForeignKeyName(Doctrine_Relation $relation)
	{
		$parts = array(
		$relation['localTable']->getTableName(),
		$relation->getLocalColumnName(),
		$relation['table']->getTableName(),
		$relation->getForeignColumnName(),
		);
		$key = implode('_', array_merge($parts, array($relation['onDelete']), array($relation['onUpdate'])));
		$format = $this->getAttribute(Doctrine_Core::ATTR_FKNAME_FORMAT);

		return $this->_generateUniqueName('foreign_keys', $parts, $key, $format, $this->getAttribute(Doctrine_Core::ATTR_MAX_IDENTIFIER_LENGTH));
	}

	/**
	 * Get/generate unique index name for a table name and set of fields
	 *
	 * @param string $tableName     The name of the table the index exists
	 * @param string $fields        The fields that makes up the index
	 * @return string $indexName    The name of the generated index
	 */
	public function generateUniqueIndexName($tableName, $fields)
	{
		$fields = (array) $fields;
		$parts = array($tableName);
		$parts = array_merge($parts, $fields);
		$key = implode('_', $parts);
		$format = $this->getAttribute(Doctrine_Core::ATTR_IDXNAME_FORMAT);

		return $this->_generateUniqueName('indexes', $parts, $key, $format, $this->getAttribute(Doctrine_Core::ATTR_MAX_IDENTIFIER_LENGTH));
	}

	protected function _generateUniqueName($type, $parts, $key, $format = '%s', $maxLength = null)
	{
		if (isset($this->_usedNames[$type][$key])) {
			return $this->_usedNames[$type][$key];
		}
		if ($maxLength === null) {
			$maxLength = $this->properties['max_identifier_length'];
		}

		$generated = implode('_', $parts);

		// If the final length is greater than 64 we need to create an abbreviated fk name
		if (strlen(sprintf($format, $generated)) > $maxLength) {
			$generated = '';

			foreach ($parts as $part) {
				$generated .= $part[0];
			}

			$name = $generated;
		} else {
			$name = $generated;
		}

		while (in_array($name, $this->_usedNames[$type])) {
			$e = explode('_', $name);
			$end = end($e);

			if (is_numeric($end)) {
				unset($e[count($e) - 1]);
				$fkName = implode('_', $e);
				$name = $fkName . '_' . ++$end;
			} else {
				$name .= '_1';
			}
		}

		$this->_usedNames[$type][$key] = $name;

		return $name;
	}
}